We are currently attempting to extend the diffraction limit of the above HIV-1 integrase crystal forms, and others, by screening various crystallization additives, inhibitors, substrate, and cryogenic artificial mother liquors. Since diffraction is significantly improved by the use of synchrotron radiation, SSRL time is clearly required for project continuation. The following experiments will be carried out: 1)Screen for conditions which improve the diffraction limit of the HIV-1 integrase crystals. 2)Minimally, collect high resolution data from apo-crystal B grown in PEG with and without inhibitor, and crystal A.